Improvement in grinding-mills



2- Sheets-Sheet 1.

M. B. ATKINSON. Grinding-M111.

No. 206,996. Patented Aug. 13,1878'.

.Aj-army.

N.FETES. PHOljQ-UTHDGHAFHER. WASHINGTON D C 2 Sheets-Sheet.

M.- B. ATKINSON .Grinding-LANL.

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UNITED STATES MAnLoN B. ATKINSON, or snnnrsnune, MARYLAND, AssIeNor. or Two- IDILITE'NT @ENIGE THIRDS OF HIS RIGHT TOV WILLIAM OAMMAOK AND GEO. YV. DECKER, OF WASHINGTON ,DISTRICT OF COLUMBIA.

IMPROVEMENT lN GRINDINe-MILLS.

Specification forming part of Letters` Patent No. 206,996, dated August 13, i878; applicationlilcd I July 31, 1878. v

To all whom fit may concern:

Be it known that I, MAHLoN B. ATKINSON, of Sharpsburg, in the county of Washington .and State of Maryland, have invented certain new and useful Improvements in Grinding- Machines, of which the following is a spccifr cation:

This invention relates to that class ot' mills in which a vertically-revolving circular stone having furrows across its periphery runs within a stationary concave stone, which isalso transversely furrowed. Its object is to provide a mill having a capacity of `production ranging from the coarsestgranulation, asin the manufacture of hominy and cracked corn forhorse-food, to the highest grade of wheat flour.

It has heretofore been necessary to use for granulating grain pairs of stones having a special dress not suited for flourin g purposes or formakin g corn-meal, this necessity arising from the fact thata dress adapted to produce iiour has a rubbing action upon the grain, and this action continues even though the stones be set so far apart as to but imperfectly crush the grain, so that with hominy, grits, or other granulated cereals producedby stones having a Iiouring-dress there has'always been found a very objection ablepercentage of flour.

The' forms of dress especially adapted for producing4 clean granulationlunmixed with iiour have not, Ysofar as I amlaw'are, been capable of any adjustment for flourin'g.` Separate pairs of stones, therefore, have always been essential to the successful and satisfactory performance of the two operations. i

By my invention the necessity for differently-dressed pairs of stones is obviated.

It consists in the combination of a vertically-rotating cylindrical stone having on its periphery the .millstonedress consisting of transverse furrows .with abrupt shoulders,

.,lands, andffeather-edges, substantially as described, and the concave stone` provided 'with a similar dress, and adjustable circumferentially to reverse positions with respect to the dress of the 'cylindrical stone for the purpose of adapting the mill to either granulatiug or tlouring purposes, substantiallyas hereinafter described and explained.

It consists, further, in a novel combination of devices for adjusting the concave to or from a cylindrical millstone; and, further, in an improved millstone-dress which prevents the grain from scattering from between the faces of a vertical millstone and its concave when the cylinder is rotated -in either direction, as hereinafter set forth.l

In the accompanying drawin gs, Figure l is a side elevation of my improved mill arranged for granulating or cracking grain. Fig. 2 is a similar view, showing the stones arranged for ilouring or Inealing. Fig. 2.* is a detail view of the adjusting-eccentric. Fig. 3 vis a plan view. Fig. iis a view in elevation, illustrating a modification tof the hopper-support, and also of the concaveadjusting devices. Fig. 5 illustrates a modiiied form especially adapted for granulating wheat. Fig. 6 isa face view of the cylindrical stone. Fig. 7 is a face view of the concave, and Fig. 8 is a perspective view of a segmentI of the face of the cylindrical stone..

The letter A indicates a vertically-rotating cylindrical grinding-stone, which may be made of burrstone or metal with chilled face, mounted in bearings upon a frame, B, and having furrows a, across its periphery. These furrows are in practice about "one-sixteenth (l-) of an inch deep, having each one abrupt wall or shoulder, b, an inclined face', c', about three-fourths eff an inch in extent, terminating at a land, d, of about the same: length, reaching totheshoulder of the next furrow.

The shouldersof the furrows do not .extendf decreasing in height and,in the-space ofabout one-quarter` of inch, vanishing on the adjacent inclined face. A Immediately behind the beveled portion ofthe shoulder of each furrow iscut a short beveled'shoulder,z, and having extensions parallel with themain furrow and with the edge of the stone, these extensions gradually decreasing in height and vanishing on the land. The purpose of bevelin g the shoulders at their ends and of the inclined short shoulders z is to direct the grain inward from the edges of the stone and prevent its scattering out from between them.

Aconcave stone, C, has its inner face dressed in the same manner and arranged opposite to the periphery of the stone A. This concave stone G has its outer portion secured in a casing, D, at the opposite ends, and on both sides of which extend two arms, E E', branching at right angles from an arm, F, which is mounted on shaft of stone A, andiheld in place by a gib, j', and key f. fN ear the outer end of each arm E E is mounted a worm-wheel, g, on an eccentric-shaft, hLand gearing with each of these worm-wheels is a worm, i, on the end of a shaft, Jr, mounted in a bearing arranged upon the side of casing D. The inner ends of these shafts k are provided with wheels l, by which they may be turned. f

The casing D fits and is movable between the arms E E at its ends, and the turning of the worm t' causes the said casing and the stone C inclosed therein to be moved closer to or farther from the cylindrical stone, as desired. As the distance between the arms E E increases toward their outer ends, the outward shifting of the stone G would loosen the threads of the worms iin the teeth of the wheels/gi or entirely detach said worms and wheels, were not some provision made to prevent it; and it is for this reason that the wheels g are mounted on eccentric axes, which are arranged to turn toward the worms as the stone moves outward, as will be readily understood. Upon the outer surface of the casing D are studs y on both sides of the eccentric-shafts, the tops of these studs being connected by a cross-bar having` its under side concaved and forming a top bearing for the eccentric shaft or roller, so that it may carry the stone outward.

In the modification shown in Fig. 4 the journals of the eccentric shafts or rollers project through the arms E E', and have attached arms w, proyided with segmental cross-arms w1, having longitudinal slots @02. Through these slots extend thumb set-screws w3. By loosening these screws the segments fw]- may be adjusted in any direction, and the throw of the eccentric-shafts changed to adjust the concave.

The hopper H is provided with ears m at its opposite sides, by which it is detachably secured by suitable screws to one end of the casing in position to feed the grain between the stones.

In Fig. l the stones are shown in position for granulatin g the grain with a clean fracture without producing flour. As the grain drops upon the stone A, revolving in the direction indicated by the arrow, it is caught by shoulder a of afurrowin stoneAand carried forward, striking the shoulder a of the concave; then the fragments falling into the furrow are not rubbed or powdered between two surfaces, but

areonly broken again when projecting sufficiently to strike another shoulder of the con.

cave, finally falling out throughspout s. By this arrangement hominy of any degree of ineness, or any other granulated or cracked grain, is produced without any adlnixture of flour.

Now, when it is desired to make flour or meal, the hopper is removed from casing D, as shown in Fig. l, and t-he arms E E turned to the position shown in Fig. 2, or;to;the opposite side of the stone A, the end p of the casing resting upon the bar u', as the end p rests upon bar n in Fig. l. The hopper is then secured to the upper end of the casing. Thev parts now being in the position as shown in Fig. 2, the direction of rotation of the stone A is to be changed by any suitable means, as, for instance, twisting the driving-belt so that the stone will travel in the direction of the arrow indicated thereon. Now, when the grain falls from the hopper it is carried by the feather-edge 0 of the furrow against the feather-edge o of the furrow of the concave, crushed and rubbed between the lands of the two stones, and a iiour produced, the iineness of which depends upon the distance apart to which the stones are adj usted. This arrangementfef/the stones may be used also for fmishing fine grades of grits.

In grinding wheat-Hour it produces a large percentage of middlings, and separates the gluten, or most nutritious and valuable portion of the grain, so perfectly from the husk as to make a grade of iiour similar to that resulting from what is known as the new process,77 and dispenses with the use of middlings-puriers necessary in said process, thus greatly economizing labor and expense of machinery.

In the modification shown in Fig. 5, which I prefer to use in granulatin g wheat or making wheaten grits, the furrows of both stones are in the same direction, the stone A turning in the direction of the arrow. When the wheat falls from the hopper into a furrow of stone A it is carried by the featheredge against the shoulder of the next furrow of the concave C', and when there broken a portion of the grain is held by the shoulder until struck and again broken by the next succeeding featheredge of a furrow of stone A', and the other portion is carried forward to be rebroken upon a shoulder of C', so that, it will be seen, the shoulders of C and feather-edges of A act at4 least twice upon the same grain, or until it is broken sufficiently fine to pass between the lands of the two stones, the distance apart of which governs the nencss of the product.

In the modification shown in Fig. 4 the hopper is supported in a square frame, Q, supported on posts q extending upward from the frame. ln this modification it is not necessary to remove the hopper in changing the position of the concave.

A revolving brush, I, operated by a belt from a pulley on the shaft of the cylindrical Y stone, is arranged across .the bottom of this stone, and serves to keep it clean.

What I claim as my invention isl. The combination of a vertically-rotating cylindrical stone having on its periphery the millstonedress consisting of transverse furrows with abrupt shoulders, lands, and feather-edges, substantially as described, and a concave stone provided with a similar dress and adjustable circumferentially to reverse positions with respect to the dress of the cylindrical stone, for the purpose of adapting the mill to either granulating or iourin g purposes, substantially as set forth.

2. The combination of the cylindrical stone AA and the concave C, mounted in a swinging frame composed of the arms E E and arm F, pivoted on the aXle of said cylindrical stone, and adapted to be shifted to opposite sides of said stone, and the stone-supporting frame provided with the bars a n', for supporting and limiting the curvilinear movement of the concave, substantially as and for the purpose set forth.

3. The combination of the stone C, arms E E', carrying the eccentrically-mounted worm- Wheels g, and the operating-Worms, substantially as described.

4. The vertically-rotating stone having on its periphery the transverse shoulders b, having extensions inclined outward at their ends toward the edges of the stone, and provided with the short shoulders z cut in the lands, and inclined oppositely to the inclined extensions of the main shoulders, substantially as and for the purpose set forth.

In testimony that I claim the foregoing I have hereunto set my hand in the presence of the subscribing witnesses.

M'. B. A'JKINSON.

W'itnesses:

J AMEs L. Nonnrs, ALBERT II. Nonnrs. 

